The 2100 class locomotives were built by Clyde Engineering in Salisbury (Brisbane) in 1970. The initial order was for 10 units for the then new Goonyella System. This was later changed to 12 units and was later added to with a further 12 units being ordered. The class eventually comprised 24 locomotives with running numbers from 2100 to 2123.

These locomotives were rated at 2,200hp and were used, by the early 1970s, in all forms of mainline traffic on the North Coast Line and ALL western lines rated for a 15 tonne axle load.